[rubyonrails@localhost rails_sandbox]$ git push heroku master

Hosting Ruby On Rails Free

Host rails 2 or rails 3 apps for free and easily

Once you set up a site, you can set up as many sites as you want

If you are a Rails developer and want to host for free for testing purpose check-out http://www.heroku.com

For this you need to sign-up for two sites first is Heroku and other is github..After sign-up go to quick start page of heroku.com and follow instructions and in the end you would have a hosted rails application